FXUS64 KOHX 221017 AAA
AFDOHX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE NASHVILLE TN
417 AM CST TUE DEC 22 2009

.UPDATE...
LATEST SHORT TERM MODEL GUIDANCE IS SUGGESTING FREEZING FOG COULD
STILL BE PRESENT AFTER 8 AM. WITH THIS IN MIND...AND IN AGREEMENT
WITH SURROUNDING OFFICES...HAVE EXTENDED THE FREEZING FOG ADVISORY
UNTIL 9 AM.
&&

.PREV DISCUSSION... /ISSUED 330 AM CST TUE DEC 22 2009/ 

.DISCUSSION...
FORECAST REASONING WILL BE BASED ON A LEAN TOWARD A MODEL CONSENSUS 
SOLUTION FOR THE FORECAST PERIOD UNLESS OTHERWISE NOTED.

CURRENTLY...SFC RIDGE EXTENDING FROM THE CNTRL GULF COASTAL REGION
INTO THE OHIO RIVER VALLEY. UPPER LEVEL FLOW GENERALLY ORIENTATED
ZONAL...WITH EMBEDDED SHORTWAVES IN FLOW. SOME PATCHES OF DENSE
CI MOVING W TO E ACROSS THE MID STATE. DEWPOINT DEPRESSIONS
GENERALLY TWO DEGREES OR LESS...WITH TEMPS LOW 30S TO MID 20S...
AND DEWPOINTS SPANNING THE 20S. MOST LOCATIONS REPORTING
CALM WINDS. PATCHY AREAS OF FREEZING FOG DEVELOPING ACROSS
THE MID STATE...LOCALLY ISOLATED DENSE...WITH BEST CONCENTRATION
ACROSS AREAS ALONG AND NORTH OF I-40 AND ALONG AND WEST OF I-24.  

FORECAST QUANDARIES...FREEZING FOG HAS DEVELOPED...BUT HAS NOT
BECOME AS WIDESPREAD AS PREVIOUSLY THOUGHT AS THE EARLY MORNING
HOURS HAVE PROGRESSED...WILL WAIT FOR PRESS TIME FOR FINAL
DECISION...BUT AM LEANING TOWARD MENTIONING PATCHY FREEZING FOG
..BUT WILL NOT MENTION DENSE...AS DENSE FREEZING FOG IS BEING
REPORTED AT ONLY A SELECT FEW LOCATIONS. THUS...WILL CONTINUE
WITH FREEZING FOG ADVISORY THRU 8 AM THIS MORNING.    

ANOTHER DAY ON GENERALLY FAIR WEATHER TODAY AS REGION BE UNDER THE 
INFLUENCE OF A WEAK RIDGING SFC AND ALOFT...WITH MAX TEMPS 5 TO 10 
DEGREES ABOVE CLIMATOLOGICAL NORMS. SFC/ALOFT RIDGING WILL MOVE E 
OF THE AREA TONIGHT...ALLOWING SELY SFC WINDS TO DEVELOP OVERNIGHT...
ALONG WITH AN INCREASE IN CLOUD COVER ASSOCIATED WITH APPROACHING
SRN PLAINS LOW PRESSURE SYSTEM...WHICH WILL HELP KEEP MIN TEMPS
IN SOME LOCATIONS AS MUCH AS 10 DEGREES ABOVE CLIMATOLOGICAL NORMS.
A SLIGHT CHANCE OF RAIN WILL ALSO BE POSSIBLE ACROSS AREAS MAINLY
ALONG AND WEST OF I-65 AFTER MIDNIGHT.  

WEATHER STARTS TO PICK UP BY WED AS STRONG UPPER LEVEL TROF MOVES 
FROM THE SRN ROCKIES INTO THE SRN PLAINS. CHANCES FOR SHWRS WILL 
INCREASE WED AS MOISTURE IMPROVES WITH WARM FRONT POSITIONED JUST
N OF THE MID STATE...BUT BEST CHANCE WILL BE THU DUE TO PROXIMITY
OF TROF...SFC FRONTAL MOVEMENT INTO W PORTIONS OF THE MID STATE
DURING THE AFTERNOON HOURS...ALONG WITH A FURTHER INCREASES IN
MOISTURE AND LIFT. ISOLATED TSTMS CAN NOT BE RULED OUT...BUT
BUT INSTABILITY MARGINAL AT BEST. EXPECT GUSTY SELY SFC WINDS THU
..AS ABOVE MENTION SFC LOW MOVES SLOWLY FROM OK INTO MO.
OCCLUDED FRONT SHOULD SWING THRU ON THU NIGHT...WITH COOLER
AND BREEZY WEATHER ON FRI. SOME CHANCE FOR PRECIP TO SWITCH
OVER TO FROZEN AROUND THE TIME THAT IT ENDS ON FRI ACROSS AREAS
GENERALLY NORTH OF I-40...W OF I-65...AND ACROSS THE CUMBERLAND
PLATEUA REGION...BUT STILL DO NOT EXPECT ANYTHING SIGNIFICANT.

MODELS CONTINUE TO SHOW THAT SOME DISTURBANCES MAY ROTATE AROUND
THE BOTTOM PORTION OF THE DEPARTING DEEP H5 LOW DURING THE WEEKEND.
HOWEVER...MOISTURE STILL LOOKS TO BE PRETTY LIMITED. BY MON...RIDGING
WILL BE PREVALENT OVER THE SRN U.S. WITH A RETURN TO FAIR WEATHER
ACROSS THE MID STATE.

THANKS FOR COORDINATION PAH...LMK...AND JKL. 

&&

.OHX WATCHES/WARNINGS/ADVISORIES...
FREEZING FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR TNZ005>011-
022>034-056>066-075-077>080-093>095.

&&

$$
31/JBW